Alkylation catalyst regeneration utilizing polyvinylpyridine and amine substituted styrene divinylbenzene copolymer contact materials

ABSTRACT

Described is a novel process for regenerating an ASO contaminated alkylation catalyst containing a sulfone component and a hydrogen halide component. A sulfone-containing mixture containing ASO and which is derived by the removal of a major portion of the hydrogen halide component of the alkylation catalyst is contacted with a reversable base selected from the group consisting of polyvinyl pyridine, amine-substituted styrene divinyl benzene copolymer and mixtures thereof so as to remove at least a portion of the ASO component from the sulfone-containing mixture to thereby produce a treated sulfone-containing mixture. The treated sulfone-containing mixture can further be processed by contacting it with an absorbent material which can include carbon and alumina.

This application is a continuation-in-part of application Ser. No.07/935,807, filed Aug. 27, 1992, now abandoned.

The present invention relates to the regeneration of a catalystcomposition utilized in a hydrocarbon conversion process. Moreparticularly, the invention relates to the regeneration of a catalystmixture, comprising a sulfone compound and a hydrogen halide compound,utilized in the alkylation of olefin hydrocarbons by isoparaffinhydrocarbons.

BACKGROUND OF THE INVENTION

It has recently been discovered that a mixture, comprising a sulfonecompound and a hydrogen halide compound, is an effective catalyst foruse in the alkylation of olefin hydrocarbons by isoparaffin hydrocarbonsto produce an alkylate reaction product, or alkylate. This discovery hasbeen disclosed or claimed, or both, in several patent applications suchas application Ser. No. 07/877,336 of Abbott and Randolph, filed May 1,1992, and application Ser. No. 07/877,338 of Abbott et al, filed May 1,1992. The alkylate reaction product generally contains hydrocarbonshaving seven or more carbon atoms, and it is a highly desirable gasolineblending component because of its high octane value as a motor fuel.

While a process which utilizes a catalyst composition comprising asulfone component and a hydrogen halide component produces an alkylateproduct of very high quality, one side effect from using such a processin the production of alkylate is the formation of certain polymericreaction by-products such as those referred to as acid-soluble oils, orASO. These polymeric reaction by-products are referred to asacid-soluble oils because they are soluble in the catalyst utilized inthe alkylation process and, thus, remain in the catalyst phase when thealkylate product resulting from the contact of a hydrocarbon mixturewith an alkylation catalyst is separated from the alkylation catalyst.In an alkylation process which continuously separates the catalyst phasefrom the alkylation reaction product for reuse in the process reactionzone, there is a buildup of ASO in the catalyst. Over time the ASOconcentration will reach unacceptable concentration levels if notremoved. A low concentration of ASO in the alkylation catalystcomprising a sulfone component and a hydrogen halide component isbelieved to have a beneficial effect upon the alkylation process or itsproduct. However, higher concentrations of ASO in the alkylationcatalyst have an adverse effect upon the catalyst activity and the finalalkylate end-product. An ASO concentration in the alkylation catalystthat exceeds certain acceptable limits will result in lowering theoctane of the alkylate end-product with incremental increases in the ASOconcentration causing incremental decreases in the alkylate octane.

In conventional alkylation process that use hydrogen fluoride (HF) as acatalyst, as opposed to the use of the aforementioned novel catalystcomprising a sulfone component and a hydrogen halide component, thereare certain known methods used to remove the ASO from the HF catalystused in a continuous alkylation process. Particularly, enough of aportion of the HF catalyst that is utilized in the alkylation process istreated, or regenerated, so as to remove an amount of ASO at a rate thatapproximates the rate of accumulation of ASO in the alkylation catalyst.This is done by passing a portion of the HF catalyst to a strippingvessel whereby the HF is stripped from the ASO by means of a vaporoushydrocarbon such as isobutane with the HF passing as a part of thevaporous overhead stream from the stripping vessel and the ASO passingas a bottoms stream from the stripping vessel for further processing.

While the conventional alkylation catalyst regeneration techniques haveworked well in the regeneration of the conventional HF catalyst,conventional means cannot be used to regenerate an alkylation catalystmixture which includes a sulfone component. This is because the boilingrange of ASO overlaps the boiling temperatures of certain sulfones suchas sulfolane. Therefore, simple distillation techniques as are used toseparate HF from ASO cannot be used to effectively regenerate asulfone-containing alkylation catalyst. Additionally, it is necessary toseparate ASO from the sulfone in order to reclaim the sulfone for reuseas a catalyst in the alkylation process.

SUMMARY OF THE INVENTION

It is, therefore, an object of this invention to provide a novel processfor the regeneration of alkylation catalysts.

A further object of this invention is to provide a process for theremoval of ASO from alkylation catalysts containing a sulfone component.

Thus, the process of the present invention relates to the alkylation ofolefin hydrocarbons by paraffin hydrocarbons by utilizing a catalystmixture that includes a sulfone component. A sulfone-containing mixturecomprising a sulfone and ASO is contacted with a reversible base underconditions suitable for the removal of at least a portion of the ASOcomponent of the sulfone-containing mixture to produce a treatedsulfone-containing mixture.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 provides schematic representation of the process which is oneembodiment of the invention;

FIG. 2 is a plot demonstrating the capacity of an activated carbon toadsorb ASO from a sulfone-containing mixture as a function of the weightpercent HF contained in such mixture; and

FIG. 3 is the ASO adsorption curve for an aliphatic amine substitutedpolymer utilized to simultaneously remove ASO and HF from sulfolanewhich contains such compounds.

Other objects and advantages of the invention will be apparent from theforegoing detailed description of the invention and the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

The acid soluble oil of the present invention is produced as a reactionby-product in an alkylation process comprising the step of contacting ahydrocarbon mixture, which comprises olefins and isoparaffins, with analkylation catalyst, which comprises, consists of, or consistsessentially of a hydrogen halide component and a sulfone component. Asused within this description and in the appended claims, the term "acidsoluble oil", or "ASO", means those conjunct polymers which are highlyolefinic oils produced by acid-catalyzed reactions of hydrocarbons. Anextensive description and characterization of certain types of conjunctpolymer oils is provided in the Journal of Chemical and Engineering Dataarticle entitled "Molecular Structure of Conjunct Polymers", pages150-160, Volume 8, Number 1, by Miron and Lee. This article isincorporated herein by reference. The physical properties of ASO dependupon the particular hydrocarbon feed processed, the catalyst utilized inthe process, feed contaminants such as hydrogen sulfide, butadiene,oxygenates and other compounds, and the alkylation process reactionconditions. Thus, as the term is more narrowly defined, ASO will bethose conjunct polymers produced as a by-product in the catalyzedreaction of mono-olefins with isoparaffins utilizing a catalyst mixturecomprising, consisting of, or consisting essentially of a sulfonecomponent and a hydrogen halide component. The preferred mono-olefinsfor use in the catalyzed reaction are those having from three to fivecarbon atoms and the preferred isoparaffins are those having from fourto six carbon atoms. The preferred sulfone component is sulfolane andthe preferred hydrogen halide component is hydrogen fluoride.

The ASO by-product derived from the hydrocarbon reaction catalyzed by asulfone-containing alkylation catalyst can be further generallycharacterized as having a specific gravity, with water at 60° F. as thereference, in the range of from about 0.8 to about 1.0, an averagemolecular weight in the range of from about 250 to about 350, and abromine number in the range of from about 40 to about 350.

The hydrogen halide component of the catalyst composition or catalystmixture can be selected from the group of compounds consisting ofhydrogen fluoride (HF), hydrogen chloride (HCl), hydrogen bromide (HBr),and mixtures of two or more thereof. The preferred hydrogen halidecomponent, however, is hydrogen fluoride, which can be utilized in thecatalyst composition in anhydrous form; but, generally, the hydrogenfluoride component utilized can have a small amount of water. In acatalyst composition including hydrogen fluoride and sulfolane, theamount of water present in no event can be more than about 30 weightpercent of the total weight of the hydrogen fluoride component, whichincludes the water. Preferably, the amount of water present in thehydrogen fluoride component is less than about 10 weight percent. Mostpreferably, the amount of water present in the hydrogen fluoridecomponent is less than 7 weight percent. When referring herein to thehydrogen halide component, or more specifically to the hydrogen fluoridecomponent, of the catalyst composition of the invention, it should beunderstood that these terms mean that the hydrogen halide component iseither an anhydrous mixture or a non-anhydrous mixture. The referencesherein to weight percent water contained in the hydrogen halidecomponent means the ratio of the weight of water to the sum weight ofthe water and hydrogen halide multiplied by a factor of 100 to place theweight ratio in terms of percent.

The sulfones suitable for use in this invention are the sulfones of thegeneral formula

    R--SO.sub.2 --R'

wherein R and R' are monovalent hydrocarbon alkyl or aryl substituents,each containing from 1 to 8 carbon atoms. Examples of such substituentsinclude dimethylsulfone, di-n-propylsulfone, diphenylsulfone,ethylmethylsulfone and the alicyclic sulfones wherein the SO₂ group isbonded to a hydrocarbon ring. In such a case, R and R' are formingtogether a branched or unbranched hydrocarbon divalent moiety preferablycontaining from 3 to 12 carbon atoms. Among the latter,tetramethylenesulfone or sulfolane, 3-methylsulfolane and2,4-dimethylsulfolane are more particularly suitable since they offerthe advantage of being liquid at process operating conditions of concernherein. These sulfones may also have substituents, particularly one ormore halogen atoms, such as for example, chloromethylethylsulfone. Thesesulfones may advantageously be used in the form of mixtures.

The alkylation catalyst used in the alkylation process wherein an ASOreaction by-product is produced can comprise, consist of, or consistessentially of a hydrogen halide component as described herein and asulfone component as described herein. Preferably, the ASO by-productwill be produced in an alkylation process in which the hydrocarbonmixture is contacted with an alkylation catalyst having sulfolane as itssulfone component and hydrogen fluoride as its hydrogen halidecomponent. In the case where the alkylation catalyst comprises sulfolaneand hydrogen fluoride, good alkylation results can be achieved withweight ratio of hydrogen fluoride to sulfolane in the alkylationcatalyst in the range of from about 1:1 to about 40:1. A preferredweight ratio of hydrogen fluoride to sulfolane can range from about2.3:1 to about 19:1 and, more preferably, it can range from 3:1 to 9:1.

In order to improve selectivity of the alkylation reaction of thepresent invention toward the production of the desirable highly branchedaliphatic hydrocarbons having seven or more carbon atoms, a substantialstoichiometric excess of isoparaffin hydrocarbon is desirable in thereaction zone. Molar ratios of isoparaffin hydrocarbon to olefinhydrocarbon of from about 2:1 to about 25:1 are contemplated in thepresent invention. Preferably, the molar ratio of isoparaffin-to-olefinwill range from about 5 to about 20; and, most preferably, it shallrange from 8 to 15. It is emphasized, however, that the above recitedranges for the molar ratio of isoparaffin-to-olefin are those which havebeen found to be commercially practical operating ranges; but,generally, the greater the isoparaffin-to-olefin ratio in an alkylationreaction, the better the resultant alkylate quality.

Alkylation reaction temperatures within the contemplation of the presentinvention are in the range of from about 0° F. to about 150° F. Lowertemperatures favor alkylation reaction of isoparaffin with olefin overcompeting olefin side reactions such as polymerization. However, overallreaction rates decrease with decreasing temperatures. Temperatureswithin the given range, and preferably in the range from about 30° F. toabout 130° F., provide good selectivity for alkylation of isoparaffinwith olefin at commercially attractive reaction rates. Most preferably,however, the alkylation temperature should range from 50° F. to 120° F.

Reaction pressures contemplated in the present invention may range frompressures sufficient to maintain reactants in the liquid phase to aboutfifteen (15) atmospheres of pressure. Reactant hydrocarbons may benormally gaseous at alkylation reaction temperatures, thus reactionpressures in the range of from about 40 pounds gauge pressure per squareinch (psig) to about 160 psig are preferred. With all reactants in theliquid phase, increased pressure has no significant effect upon thealkylation reaction.

Contact times for hydrocarbon reactants in an alkylation reaction zone,in the presence of the alkylation catalyst of the present inventiongenerally should be sufficient to provide for essentially completeconversion of olefin reactant in the alkylation zone. Preferably, thecontact time is in the range from about 0.05 minute to about 60 minutes.In the alkylation process of the present invention, employingisoparaffin-to-olefin molar ratios in the range of about 2:1 to about25:1, wherein the alkylation reaction mixture comprises about 40-90volume percent catalyst phase and about 60-10 volume percent hydrocarbonphase, and wherein good contact of olefin with isoparaffin is maintainedin the reaction zone, essentially complete conversion of olefin may beobtained at olefin space velocities in the range of about 0.1 to about200 volumes olefin per hour per volume catalyst (v/v/hr.). Optimum spacevelocities will depend upon the type of isoparaffin and olefin reactantsutilized, the particular compositions of alkylation catalyst, and thealkylation reaction conditions. Consequently, the preferred contacttimes are sufficient for providing an olefin space velocity in the rangeof about 0.1 to about 200 (v/v/hr.) and allowing essentially completeconversion of olefin rectant in the alkylation zone.

The alkylation process can be carried out either as a batch orcontinuous type of operation, although it is preferred for economicreasons to carry out the process continuously. It has been generallyestablished that in alkylation processes, the more intimate the contactbetween the feedstock and the catalyst the better the quality ofalkylate product obtained. With this in mind, the present process, whenoperated as a batch operation, is characterized by the use of vigorousmechanical stirring or shaking of the reactants and catalyst.

In continuous operations reactants can be maintained at sufficientpressures and temperatures to maintain them substantially in the liquidphase and then continuously forced through dispersion devices into thereaction zone. The dispersion devices can be jets, nozzles, porousthimbles and the like. The reactants are subsequently mixed with thecatalyst by conventional mixing means such as mechanical agitators orturbulence of the flow system. After a sufficient time, the product canthen be continuously separated from the catalyst and withdrawn from thereaction system while the partially spent catalyst is recycled to thereactor. A portion of the catalyst can continuously be regenerated orreactivated as described herein, or by any other suitable treatment, andreturned to the alkylation reactor.

One embodiment of this invention includes a process for removing ASOfrom a sulfone-containing mixture comprising the step of contacting asulfone-containing mixture, comprising a sulfone component and ASO, witha contact material suitable for the removal of at least a portion of theASO component of said sulfone-containing mixture to produce a treatedsulfone-containing mixture. The sulfone-containing mixture of theinventive process can also comprise a sulfone component, a hydrogenhalide component, and ASO. The contact material can be those materialsdescribed herein and can include materials selected from the groupconsisting of alumina, carbon, and mixtures thereof as well as thepreferred reversible bases as are defined herein. The preferred sulfonecomponent of the sulfone-containing mixture is sulfolane.

The ASO component of the sulfone-containing mixture can be present in anamount no more than about 20 weight percent of the sulfone component.Preferably, the concentration of ASO is less than about 15 weightpercent of the sulfone component, and most preferably, the ASO will bepresent at a concentration of less than 10 weight percent. When ahydrogen halide component is present in the sulfone-containing mixture,its concentration will be less than about 10 weight percent of themixture with the weight percent determined by the weight fraction of thehydrogen halide to total sum weight of hydrogen halide and sulfonemultiplied by a factor of 100 to yield a percent. But, generally, theconcentration range of hydrogen halide in the sulfone-containing mixturecan range from about 0.1 weight percent to about 10 weight percent.Preferably, however, the concentration can range from about 0.1 to about7.5 weight percent, and most preferably, it can range from 0.1 to 5.0weight percent.

It is an important, if not critical, aspect of this invention for thecontacting of the sulfone-containing mixture with the contact materialto result in removal of at least a portion of the hydrogen halidecomponent of the sulfone-containing mixture to give the treatedsulfone-containing mixture having a reduced concentration of hydrogenhalide. It is preferred, however, to have a significant portion of thehydrogen halide component removed from the treated sulfone-containingmixture to give a concentration of the hydrogen halide component in thetreated sulfone-containing mixture of less than about 1.0 weightpercent, but preferably, the concentration will be less than about 0.2weight percent, and most preferably, the concentration will be less than0.1 weight percent.

The treated sulfone-containing mixture can also have a reducedconcentration of ASO, generally being less than about 5 weight percentof the treated sulfone-containing mixture. The preferred concentrationof ASO in the treated sulfone-containing mixture will be an amount lessthan about 2 weight percent, and most preferably, the ASO will bepresent in an amount less than 1 weight percent.

Another embodiment of the process of this invention contemplates theresolution of problems associated with the regeneration ofsulfone-containing alkylation catalyst mixtures, comprising a sulfonecomponent, a hydrogen halide component, and ASO, by the removal of atleast a portion of the ASO contained within such mixtures. Theaccumulation of ASO in a sulfone-containing alkylation catalyst occurswhen an alkylation process continuously reuses its catalyst. In acontinuous alkylation process, the ASO reaction by-product will build upin the catalyst until, if not removed, it reaches unacceptableconcentration levels that can have negative effects upon the catalystperformance and, ultimately, the alkylation product quality itself. Itis generally desirable to maintain the concentration of ASO in thesulfone-containing alkylation catalyst at no more than about 20 weightpercent of the catalyst with the weight percent ASO being based upon thetotal weight of the catalyst mixture exclusive of the ASO component.Preferably, the concentration of the ASO in the sulfone-containingalkylation catalyst is less than about 15 weight percent, and mostpreferably, the concentration of ASO is less than 10 weight percent.

While there may be some process advantages in maintaining a lowconcentration of ASO in the sulfone-containing catalyst mixture, it isbelieved that an ASO concentration exceeding about 10 weight percent ofthe catalyst will have a detrimental effect upon the catalystperformance. Thus, in order to maintain the catalyst activity of asulfone-containing alkylation catalyst mixture, at least a portion ofthe catalyst must be processed to remove at least a portion of the ASOcontained within such catalyst. To achieve this, the sulfone-containingalkylation catalyst mixture is contacted with a contact materialfollowed by contacting with an adsorbent material so as to remove atleast a portion, and preferably a substantial portion, of the ASOcomponent of the sulfone-containing alkylation catalyst mixture.

It is noted, however, that it is generally desirable to have at least aportion, and preferably a substantial portion, of the hydrogen halidecomponent of the sulfolane-containing alkylation catalyst mixtureremoved prior to contacting the resultant sulfone-containing mixturewith the contact material to thereby remove at least a portion of theASO component or remove at least a portion of the hydrogen halidecomponent, or both. Therefore, the sulfone-containing mixture will bethe sulfone-containing alkylation catalyst mixture having at least aportion, and preferably a substantial portion, of the hydrogen halidecomponent removed. Any suitable method can be used to separate thehydrogen halide component from the sulfone-containing alkylationcatalyst mixture, such as, for example, flash separation, distillation,extraction, stripping, and other suitable separation methods. Onepreferred method is by stripping means for separating thesulfone-containing alkylation catalyst mixture into an overhead stream,comprising a major portion of the hydrogen halide component of thesulfone-containing alkylation catalyst, and a bottom stream, comprisingthe sulfone-containing mixture, with the use of vaporous isobutane asthe stripping agent.

Generally, the concentration of the hydrogen halide component in thesulfone-containing mixture will be less than about 10 weight percent ofthe mixture with the weight percent determined by the weight fraction ofthe hydrogen halide to the sum total weight of hydrogen halide andsulfone multiplied by a factor of 100 to yield a percent. But, becauseit is very difficult to remove the entire amount of hydrogen halide fromthe mixture, the lower limit of hydrogen halide concentration from acommercially practical standpoint can approach about 0.1 weight percent,but, preferably, the concentration can be less than 0.1 weight percent.Thus, the concentration range of hydrogen halide in thesulfone-containing mixture can range from about 0.1 weight percent toabout 10 weight percent. Preferably, however, the concentration canrange from about 0.1 to about 7.5 weight percent, and most preferably,it can range from 0.1 to 5.0 weight percent.

The treated sulfone-containing mixture as earlier described herein canfurther be contacted in a second contacting step with an adsorbentmaterial preferably selected from the group consisting of carbon,alumina and mixtures thereof under conditions suitable for removing atleast a portion of the ASO contained therein. It is preferred, however,for a substantial portion of the ASO in the treated sulfone-containingmixture to be removed by contacting it with the adsorbent material togive a substantially ASO free sulfone-containing mixture which can havea concentration ASO free sulfone-containing mixture which can have aconcentration of ASO generally less than about 2 weight percent of thesubstantially ASO free sulfone-containing mixture. The preferred ASOconcentration is less than about 1 weight percent and most preferablythe ASO will be present in an amount less than 0.1 weight percent.

Generally, both the contact materials and the adsorbent materialscontemplated for use by this invention are in the form of solidparticulate material and can be contained as a bed within a vesseldefining a contacting zone in which the sulfone-containing fluids can becontacted with either the contact materials or the adsorbent materials.However, this invention is not confined to the use of standard vesselsfor defining a contacting zone, but any suitable means known in the artcan be utilized for contacting the sulfone-containing fluids with eitherthe contact materials or the adsorbent materials.

The adsorbent material utilized to remove ASO from the treatedsulfone-containing mixture can be any adsorbent that can either suitablyor effectively remove at least a portion of the ASO component containedin such mixture. Preferably, the adsorbent material is selected from thegroup consisting of alumina, carbon and mixtures thereof.

The carbon adsorbent material can be any activated carbon material thatis suitable for use as contemplated by this invention and for theselective removal of at least a portion of the ASO component containedin the treated sulfone-containing mixture. The activated carbonadsorbent can be characterized by its large specific surface area whichcan range from about 300 m² /g to about 2500 m² /g as determined by theAmerican Society for Testing Materials (ASTM) Standard Test MethodD3663-84 entitled "Standard Test Method for Surface Area of Catalysts".The standard ASTM test D3663-84 is incorporated herein and made a parthereto by reference. Also, the activated carbon adsorbent can further becharacterized by its pore diameter which can range from about 10 μm toabout 50 μm as determined by the method of mercury intrusion porosimetrydescribed by ASTM Standard Test D4284-88 entitled "Standard Test Methodfor Determining Pore Volume Distribution of Catalysts by MercuryIntrusion Porosimetry". The standard ASTM test D4284-88 is incorporatedherein and made a part hereto by reference. It is generally desirable touse commercially available activated carbon. One such suitablecommercially available activated carbon, for example, is the productknown by its tradename as Calgon Filtrasorb 400, which is manufacturedand marketed by Calgon Carbon Corporation.

The alumina adsorbent material can be any alumina suitable for use ascontemplated by this invention and for the selective removal of at leasta portion of the ASO component contained in the treatedsulfone-containing mixture or for use as a neutralizing agent for theremoval of at least a portion of the hydrogen halide component of asulfone-containing fluid. Such suitable aluminas include, for example, avariety of the commercially available activated aluminas and calcinedaluminas. Generally, the alumina material will have a surface area inthe range of from about 150 m² /g to about 500 m² /g as determined byASTM D3663-84. Also, the pore diameter of the alumina material can rangefrom about 25 μm to about 125 μm as determined by ASTM D4284-88. It isgenerally desirable to use commercially available aluminas. One suchsuitable commercially available alumina is the product known by itstradename HF-200 manufactured and marketed by Alcoa. The most preferredalumina for use in this invention is a calcined alumina having a gammacrystalline structure, also known as gamma-alumina, and other aluminas,such as chi-alumina having surface areas greater than about 50 m² /g.

The process conditions under which the treated sulfone-containingmixture is contacted with an adsorbent composition can be any conditionsthat are suitable or effective for removing at least a portion of theconcentration of ASO from the treated sulfone-containing mixture. Theremoval efficiency of the adsorbent material is not believed to behighly dependent upon the contact pressure because the adsorptionphenomenon is thought to be the result of a liquid-solid interaction;however, the process pressure should exceed about 0.5 atmospheres ofabsolute and can range upwardly to about 30 atmospheres, or more, ofabsolute pressure. The more common operating pressure will generallyrange from about atmospheric pressure to about 200 pounds per squareinch of gauge pressure (psig).

As for the contacting temperature, any suitable temperature can beutilized that provides for an effective removal of at least a portion ofthe ASO from the treated sulfone-containing mixture. Generally, theupper and lower temperature limits are set by the physicalcharacteristics of the mixture being treated and the physicalcharacteristics of the ASO contained in such mixture. Considering thelower temperature limit, pure sulfolane has a melting point of about81.3°-82.0° F., but when sulfolane in the form of a mixture with waterand hydrogen fluoride, the melting point is significantly lower.Therefore, the lower limit for the contacting temperature approximates0° F. As for the upper temperature limit, it is determined by suchfactors as the initial boiling temperature of the ASO and thetemperature at which the sulfone component of the mixture begins tothermally decompose. Thus, the upper contacting temperature approximates400° F. Therefore, the contact temperature generally will range fromabout 0° F. to about 400° F. Preferably, the contacting temperature willrange from about 50° F. to about 350° F., and most preferably, it willrange from 60° F. to 325° F.

It has been determined that, in the process of removing ASO from atreated sulfone-containing mixture by contacting it with an adsorbentmaterial, the presence of even a small concentration of a hydrogenhalide compound, particularly hydrogen fluoride, in the mixture has theeffect of reducing the ability of an activated carbon adsorbent toselectively remove ASO from the mixture. As illustrated by the datapresented in FIG. 2, a small concentration of hydrogen fluoride in asulfone-containing fluid being contacted with an activated carbonmaterial can have the effect of essentially rendering the carbonineffective for ASO removal. Thus, one important, and potentiallycritical, aspect of this invention is for an ASO contaminatedsulfone-containing mixture to be substantially free of a concentrationof hydrogen halide or, more generally, for the ASO contaminatedsulfone-containing mixture to be neutralized prior to, or concurrentlywith, contacting the mixture with a carbon material. Any means suitablefor the removal of at least a portion, and preferably, a significantportion, of a concentration of hydrogen halide from an ASO contaminatedsulfone-containing mixture or composition can be used. Alternatively,any neutralizing agent suitable for the removal of at least a portion ofthe hydrogen halide contained in an ASO contaminated sulfone-containingmixture can be used. Examples of such suitable neutralizing agents caninclude, but are not limited to, basic hydroxides, such as those ofalkali and alkaline earth metals, e.g., KOH, Ca(OH)₂, and NaOH; basicoxides, such as zinc oxide and tin oxide; amphoteric oxides, such asaluminum oxide; and reversible bases. Preferred neutralizing agents caninclude the various types of aluminas, hydroxide compounds andreversible bases with the most preferred neutralizing material beingeither gamma-alumina or reversible bases.

The term "reversible base" as used herein refers to an aromatic or anon-aromatic compound, which has one or more nitrogen atoms, or apolymer with pendant nitrogen atoms, wherein the nitrogen atom issterically hindered in a manner such that the salt formed by thenitrogen atom and a strong protic base will undergo dissociation to thenitrogen compound and the protic acid at a temperature below thedecomposition temperature of the nitrogen compound.

Suitable reversible bases are compounds which correspond to one of thefollowing formulas: ##STR1## or is a polymer containing unitscorresponding to one of the following formulas ##STR2## wherein

R¹ is separately in each occurrence C₂₋₂₀ alkyl, C₆₋₂₀ aryl, C₇₋₂₀alkaryl, C₇₋₂₀ aralkyl or C₃₋₂₀ cycloalkyl, wherein the C₂₋₂₀ alkyl,C₆₋₂₀ aryl, C₇₋₂₀ aralkyl, C₇₋₂₀ alkaryl or C₃₋₂₀ cycloalkyl isunsubstituted or substituted with a halo, nitro, cyano, C₁₋₂₀ alkoxy,C₆₋₂₀ aryloxy, C₇₋₂₀ alkaryloxy or C₇₋₂₀ aralkoxy; R² and R³ areseparately in each occurrence C₁₋₂₀ alkyl, C₆₋₂₀ aryl, C₇₋₂₀ alkaryl,C₇₋₂₀ aralkyl, C₃₋₂₀ cycloalkyl, nitro, cyano, halo, C₁₋₂₀ alkoxy, C₆₋₂₀aryloxy, C₇₋₂₀ alkaryloxy or C₇₋₂₀ aralkoxy wherein the C₁₋₂₀ alkyl,C₆₋₂₀ aryl, C₇₋₂₀ alkaryl, C₇₋₂₀ aralkyl, C₁₋₂₀ alkoxy, C₆₋₂₀ aryloxy,C₇₋₂₀ alkaryloxy, C₇₋₂₀ aralkoxy or C₃₋₂₀ cycloalkyl group isunsubstituted or substituted with a halo, nitro, cyano, C₁₋₂₀ alkoxy,C₆₋₂₀ aryloxy, C₇₋₂₀ alkaryloxy or C₇₋₂₀ aralkoxy;

a is separately in each occurrence an integer of from 0 to 4;

b is separately in each occurrence an integer of from 0 to 3;

c is separately in each occurrence the integer 0 or 1; and

d is separately in each occurrence the integer of from 0 to 2. Examplesof preferred reversible bases include 2,4,6-tri-t-butylpyridine,2,6-di-t-butyl-4-methylpyridine, 2,6-di-t-butylpyridine,2-t-butylpyridine, 2-benzylpyridine, 2,6-diphenylpyridine,2-phenylpyridine, 2,6-dimethoxypyridine, 2-phenoxypyridine,2,6-diphenoxypyridine, 2-methylquinoline, 6-methylquinoline,7,8-benzoquinoline, and the like. More preferred reversible basesinclude 2,4,6-tri-t-butylpyridine, 2,6-di-t-butyl-4-methylpyridine,2,6-di-t-butylpyridine, 2-t-butylpyridine, 2-benzylpyridine,2,6-diphenylpyridine, 2-phenylpyridine, 2-phenoxypyridine,2,6-diphenoxypyridine and 2,6-dimethoxypyridine.

The polyvinyl pyridine resins useful in this invention includehomopolymers of vinyl pyridine compounds, which are appropriatelysterically hindered, and copolymers of vinyl pyridine compounds with1,2-ethylenically unsaturated compounds, for example, styrene,divinylbenzene, ethylene, vinyl chloride, and the like. Furthermore, thevinylpyridines may be polymerized with 2 or more of such1,2-ethylenically unsaturated compounds. Such polymerization processesare well-known in the art. See for example, D'Aelio, U.S. Pat. No.2,623,013; Kirk-Othmer Encyclopedia of Chemical Technology, 3rd Ed.,Vol. 21, p. 816 et seq. and Vol. 19, pp. 475-76. These publications areincorporated herein by reference.

In the hereinbefore presented formulas R¹ is preferably C₃₋₁₀ alkyl,C₆₋₁₀ aryl, C₇₋₁₀ alkaryl, C₇₋₁₀ aralkyl, C₅₋₁₀ cycloalkyl, C₆₋₁₀aryloxy and C₇₋₁₀ alkaryloxy. More preferably R¹ is C₃₋₁₀ alkyl, C₇₋₁₀alkaryloxy, C₆₋₁₀ aryloxy or C₆₋₁₀ aryl; R¹ is most preferablyisopropyl, isobutyl, t-butyl, phenoxy, or phenyl. R² is preferably haloor C₁₋₁₀ alkyl. R² is more preferably C₁₋₃ alkyl. R³ is preferablyC₂₋₁₀, C₆₋₁₀, C₆₋₁₀ aryloxy or C₇₋₁₀ alkaryloxy. R³ is more preferablyC₃₋₁₀ alkyl, phenoxy or phenyl. R³ is most preferably isopropyl,isobutyl, t-butyl, phenoxy or phenyl. Preferably, a is an integer offrom 0 to 2, and most preferably 0 or 1. Preferably, b is an integer of0 or 1. Preferably, d is an integer of 0 or 1.

Other reversible bases which can suitably be utilized as a part of theprocesses described herein correspond to one of the following formulas:##STR3## wherein R is separately in each occurrence hydrogen or C₁₋₂₀alkyl and X is a halogen ion. Preferably, R is a methyl group and X ischlorine. Thus, the resin material most useful in this invention, inaddition to the polyvinylpyridine resins, are amine substituted styrenedivinylbenzene copolymers.

The polyvinylpyridine materials or resins and the amine substitutedstyrene divinylbenzene copolymer materials or resins useful asreversible bases in the invention, thus, generally includestyrene/divinylbenzene copolymers on which nitrogen-containing groupsare attached during or after polymerization. The basic functional groupsare attached to the polymer backbone by either carbon-carbon bonds, forexample, polyvinylpyridine, or by carbon-nitrogen bonds, for example,dialkylamine or trialkylammonium hydrohalide resins. The basicfunctional groups are incorporated into the polymer by any conventionaltechnique known in the art. The preferred reversible bases for use inthe invention are those polymers that are in solid particulate form atstandard conditions and which are selected from the group consisting ofpolyvinylpyridine, amine substituted styrene divinyl benzene copolymerand mixtures thereof. The most preferred reversible bases, however, arethose selected from the group consisting of poly-(2-vinylpyridine),poly-(4-vinylpyridine), and mixtures thereof.

It is desirable that the reversible bases used for this invention have apurity of above 90 percent, preferably above 95 percent and mostpreferably above 99 percent by weight. The boiling temperatures of thebases should preferably be at least 20 degrees above the thermaldissociation temperature under dissociation conditions.

One problem associated with the use of many types of neutralizing agentsis their non-regenerability. Many neutralizing agents, when they areused to remove a hydrogen halide component from a liquid medium,particularly a sulfone-containing mixture comprising a sulfone componentand ASO, eventually become spent; therefore, requiring costlyreplacement. Because of the many known disadvantages associated with theuse of non-regenerable neutralizing materials, it is desirable to use amaterial that can be regenerated and repeatedly reused. Thus, thereversible base described herein provides a preferred neutralizingmaterial, or contact material, for removing hydrogen halide from an ASOcontaminated sulfone-containing mixture or a sulfone-containing mixturecomprising a sulfone component and ASO.

While an important aspect of the invention described herein includestaking advantage of the physical properties of reversible bases so as touse them as a neutralizing material to remove hydrogen halide fromsulfone-containing mixtures described herein, it has been discoveredthat such reversible bases also have certain adsorption properties.Therefore, when a liquid medium containing ASO, such as an ASOcontaminated sulfone-containing mixture, is contacted with a reversiblebase such as poly(vinylpyridine), at least a portion of the ASOcomponent is removed from the sulfone-containing mixture by adsorptiononto the reversible base. Over time, the combination of the hydrogenhalide removed from a sulfone-containing mixture and ASO adsorption willcause the reversible base to become spent thereby necessitating itsregeneration.

One traditional method known for regenerating a spent reversible base,which has previously been exposed to a liquid medium containing a strongprotic acid, is to expose the resultant salt to thermal energy tothereby cause the salt to dissociate and librate the protic acid. Thistraditional means for regenerating a spent reversible base is notsuitable, however, when the reversible base has been exposed to asulfone-containing mixture having a concentration of ASO. It is believedthat one possible reason for the inadequate thermal regeneration of aspent reversible base that has been contacted with a sulfone-containingmixture having a concentration of ASO is due to the aforementionedabsorption characteristics of the reversible base. When a reversiblebase is utilized as an agent for removing hydrogen halide from an ASOcontaminated sulfone-containing mixture, at least a portion of the ASOconcentration of the sulfone-containing mixture is adsorbed by thereversible base thus contaminating the reversible base and rendering itless efficient as an agent for removing hydrogen halide from a liquidmedium or a neutralizing agent.

It has been discovered that the ASO adsorbed by the reversible basecannot substantially be removed exclusively by thermal means, therefore,requiring the use of other means for the removal of the adsorbed ASO.One such means is exposing the spent reversible base to a solvent underconditions such that at least a portion of the ASO adsorbed by thereversible base is removed. It is preferred that a significant portionof the ASO adsorbed by the reversible base be removed by the exposure ofthe reversible base to the solvent.

Any solvent can be used to expose or contact the spent reversible baseprovided the solvent suitably removes at least a portion of the adsorbedASO or, alternatively, removes a significant portion of the adsorbedASO. Such suitable solvents can be those solvents in which ASO issoluble and can include organic solvents selected from the groupconsisting of alcohols, aliphatic hydrocarbons, alkyl halides, amines,aromatic hydrocarbons, esters, glycols, glycol ethers, aromatic halidesand mixtures of two or more thereof.

The spent reversible base, after having been exposed to the solvent, isthen exposed to a stripping fluid under conditions suitable for removinga substantial portion of the remaining adsorbed ASO not removed by thesolvent and to remove at least a portion, preferably, a substantialportion, of the hydrogen halide removed from the sulfone-containingmixture. The stripping fluid can be any fluid which suitably performsthe stripping function described herein including, for example, water,hydrocarbons and inert gases. It is desirable for the stripping fluid tobe used in the gaseous phase. The hydrocarbons which can suitably beused as a stripping fluid include methane, ethane, propane, butane,pentane, hexane, heptane, octane and mixtures of two or more thereof,but the most preferred stripping hydrocarbon is isobutane. Nitrogen isthe preferred inert stripping gas.

The conditions under which the reversible base is stripped or exposed toa stripping fluid are such that a regeneration of the reversible base iseffected, and it is generally a thermal process whereby the spentreversible base is regenerated by use of thermal energy. Therefore, thestripping temperature is preferably in the range of from about 100° F.to about 600° F. When isobutane is used as the stripping fluid, it ispreferred for it to be in the supercritical state in order to achievethe best regeneration results. The stripping pressure is not animportant aspect of the invention and can range from about 0.1 to about140 atmospheres.

As earlier described herein, it is desirable for the hydrogen halidecomponent of the ASO contaminated sulfone-containing alkylation catalystmixture to be minimized before contacting the resultantsulfone-containing mixture with a neutralizing agent such as areversible base. In particular, when a significant portion of thesulfone-containing alkylation catalyst mixture comprises hydrogenhalide; for instance, when the weight ratio of hydrogen halide tosulfolane is in the range of from about 1:1 to about 40:1, it ispreferable for a major portion of the hydrogen halide to be removed fromthe catalyst mixture to give a sulfone-containing mixture or a recoveredcatalyst mixture. This sulfone-containing mixture or recovered catalystmixture can comprise, consist of, or consist essentially of a sulfonecomponent, a hydrogen halide component, and ASO. Generally, theconcentration of the hydrogen halide component in the recovered catalystmixture will be less than about 10 weight percent of the catalystmixture with the weight percent determined by the weight fraction of thehydrogen halide to total weight of hydrogen halide and sulfonemultiplied by a factor of 100 to yield a percent. Because it is verydifficult to remove the entire amount of hydrogen halide from thecatalyst mixture, the lower limit of hydrogen halide concentration canapproach about 0.1 weight percent, but, preferably, the lowerconcentration limit of hydrogen halide can be less than 0.1 weightpercent. Thus, the concentration range of hydrogen halide in therecovered catalyst mixture can range from about 0.1 weight percent toabout 10 weight percent. Preferably, however, the concentration canrange from about 0.1 to about 7.5 weight percent, and most preferably,it can range from 0.1 to 5.0 weight percent.

As for the use of the neutralizing agent or neutralizing material, therecovered catalyst mixture, having a concentration of hydrogen halide,is contacted with the neutralizing material to thereby remove asignificant portion of the hydrogen halide component of the recoveredcatalyst mixture to produce a neutralized sulfone-containing mixture.The neutralized sulfone-containing mixture will be significantly free ofhydrogen halide; and, generally, it will have a concentration of lessthan about 1.0 weight percent. Preferably, the neutralizedsulfone-containing catalyst mixture will have a concentration of lessthan about 0.2 weight percent, and most preferably, it will have lessthan 0.1 weight percent hydrogen halide.

The neutralization of the recovered catalyst mixture or thesulfone-containing mixture will permit further processing or treatmentof the neutralized sulfone-containing mixture or the resultant treatedsulfone-containing mixture to remove at least a portion of the ASOcomponent not removed during the neutralization step. A significantportion of the ASO component of the neutralized catalyst is removed bycontacting it with an adsorbent material suitable for removing asignificant portion of the ASO component contained therein to produce aregenerated catalyst mixture or a treated sulfone-containing mixture.The ASO component of the regenerated catalyst mixture or the treatedsulfone-containing mixture will, in most instances, be present in aconcentration of less than about 2 weight percent of the total weight ofthe sulfone component. Preferably, the weight percent of ASO present inthe treated sulfone-containing mixture can be less than about 1.0, andmost preferably, the ASO will be present in an amount less than 0.1weight percent. The regenerated catalyst mixture or treatedsulfone-containing mixture can be reused as a portion of asulfone-containing alkylation catalyst mixture comprising, consistingof, or consisting essentially of a sulfone and a hydrogen halide.

Now referring to FIG. 1, there is depicted by schematic representationan alkylation process 10. A hydrocarbon feed mixture, comprising olefinsand isoparaffins, is introduced into reactor-riser 12 through conduit14. Reactor-riser 12 defines a reaction zone wherein the hydrocarbonmixture is contacted, or admixed, with a catalyst mixture, comprisingsulfolane and hydrogen fluoride, in order to produce a reaction productand a reaction by-product. The olefins of the hydrocarbon feed mixturegenerally comprise one or more olefins having from three to five carbonatoms, and the isoparaffins of the hydrocarbon feed mixture generallywill have from four to six carbon atoms. The catalyst mixture isintroduced into reactor-riser 12 via conduit 16. The admixture ofhydrocarbon feed mixture and catalyst mixture passes through thereaction zone defined by reactor-riser 12 wherein a reaction takes placein which the olefins of the hydrocarbon feed mixture react withisoparaffins of the hydrocarbon feed mixture to produce an alkylatereaction product. Also, within the reaction zone, the reactionby-product, ASO, is formed. The reaction effluent from reactor-riser 12passes to settler vessel 18, which defines a separation zone forseparating the alkylate reaction product from the catalyst mixture toproduce a separated reaction product 20 and a separated catalyst mixture22. The separated catalyst mixture 22 will contain a substantial amountof the alkylation reaction by-product, ASO. The separated reactionproduct 20 passes to downstream processing via conduit 21. The separatedcatalyst mixture 22 can be recycled via conduits 24 and 16 toreactor-riser 12 for reuse as the alkylation catalyst mixture.Interposed in conduit 24 is catalyst cooler 26, which defines a heattransfer zone for exchanging heat from separated catalyst mixture 22 toa heat transfer fluid such as water.

At least a portion, sometimes referred to as a slip stream or a dragstream, of the separated catalyst mixture 22 passes by way of conduit 28to stripping column 30, which defines a separation zone for separatingthe slip stream of separated catalyst mixture 22 into an overheadstream, comprising a major portion of the hydrogen fluoride contained inthe slip stream, and a bottoms stream, comprising a major portion of thesulfolane component of the slip stream. The bottoms stream will alsocontain a major portion of the reaction by-product, ASO, contained inthe slip stream. Introduced into stripping column 30 by way of conduit32 is vaporous isobutane for stripping the hydrogen fluoride from theslip stream. The overhead stream passes by way of conduit 34 to settlervessel 18 wherein the hydrogen fluoride is recombined with the separatedcatalyst mixture 22 for reuse, and the stripping isobutane is combinedwith the separated reaction product 20.

The bottoms stream from stripping column 30 passes by way of conduit 36to first contacting vessel 38, which contains a contact material, saidcontact material is preferably a reversible base and most preferably apolyvinylpyridine compound. First contacting vessel 38 defines aseparation zone for removing by adsorption or by neutralization, orboth, of a substantial portion of the hydrogen fluoride contained in thebottoms stream to produce a neutralized bottoms stream or a treatedsulfone-containing mixture. Also, at least a portion of the ASOcontained in the bottoms stream is adsorbed by the contact material andthereby removed therefrom.

The neutralized bottoms stream then passes through conduit 40 to secondcontacting vessel 42, which contains an adsorbent material and defines aseparation zone for removing a substantial portion of the ASO containedin the neutralized bottoms stream to produce a regenerated catalyst, orsulfolane stream, that is substantially free of ASO and hydrogenfluoride. This sulfolane stream passes through conduit 44 to settlervessel 18 wherein it is remixed with separated catalyst mixture 22 forreuse as the sulfolane component of the alkylation catalyst mixture. Thesulfolane stream can optionally pass by way of conduit 45 to downstreamprocessing.

To regenerate the contact material contained within first contactingvessel 38, conduits 46 and 48 each respectively having valves 50 and 52are provided to permit the periodic regeneration of the spent contactmaterial. Periodically, the contact material in contacting vessel 38 isexposed to a solvent which passes by way of conduit 46 into firstcontacting vessel 38 to thereby expose the contact material underconditions such that at least a portion of the ASO adsorbed by thecontact material is removed by the solvent. The solvent containing theASO which has been removed from the contact material leaves firstcontacting vessel 38 by way of conduit 48 to downstream processing.Following the exposure of the contact material with a solvent suitablefor the removal of at least a portion of the ASO contained upon thecontact material, the previously exposed contact material is exposed toa stripping fluid. The stripping fluid can pass by way of conduit 46into first contacting vessel 38 to expose the contact material containedtherein under conditions so as to regenerate the contact material. Thestripping fluid is conveyed from first contacting vessel 38 by way ofconduit 48.

The following examples demonstrate the advantages of the presentinvention. These examples are by way of illustration only, and are notintended as limitations upon the invention as set out in the appendedclaims.

EXAMPLE I

An ASO by-product derived from the hydrocarbon reaction catalyzed by acatalyst mixture of sulfolane and HF was obtained to determine some ofits physical properties. The catalyst mixture used in the hydrocarbonreaction contained a weight ratio of HF to sulfolane of about 1.5, andthe hydrocarbon charge included isobutane and 2-butenes (60% trans, 40%cis isomers) with a molar ratio of isobutane to 2-butenes of about 11.The reaction temperature was about 90° F., and the reaction pressure wasabout 90 psig. Table I presents certain physical properties, including adistillation, of the resultant ASO obtained from the hydrocarbonreaction.

                  TABLE I                                                         ______________________________________                                        Distillation of the ASO derived from hydrocarbon reaction                     catalyzed by a sulfolane/HF catalyst mixture and other                        physical properties of the ASO.                                                                          Bromine Number of                                  Temperature °F.                                                                   Volume % of Sample                                                                            Fraction                                           ______________________________________                                         70-200    19              51                                                 200-210     8              45                                                 210-225    18              56                                                 225-250    15              58                                                 >250       40              59                                                 ______________________________________                                        Bromine Number of ASO                                                                        32                                                             API Gravity (60° F.)                                                                  37.1                                                           Specific Gravity (60° F.)                                                             0.8391                                                         ______________________________________                                    

EXAMPLE II

This Example II describes generally the experimental method used toobtain data relating to the adsorption properties of carbon, alumina,and mixtures thereof and the neutralization properties of alumina.

The general experimental procedure for testing the use of the materialsof carbon or alumina, or both, in the recovery of ASO from asulfolane-containing mixture of sulfolane and ASO included the use of aglass cylinder of approximately one inch in diameter and from 12 inchesto 24 inches in length. Placed in the bottom of the cylinder was eitherglass wool or glass beads to provide support for the active material,and on top of the active material was placed either glass beads or glasswool to assist in providing an even distribution of thesulfolane-containing mixture over the active material. Heat wasoptionally provided to the glass cylinder to induce the flow of thesulfolane-containing mixture through the bed of active material. Thesulfolane-containing mixture had a weight ratio of sulfolane-to-ASO ofapproximately 9 to 1. The color of the resultant filtrate provided anindication as to when the adsorption capacity of the active material wasspent and thus was monitored to determine when the experiment wascomplete.

EXAMPLE III

This Example III illustrates the unexpected relationship between thecapacity of activated carbon to adsorb ASO from a sulfolane-containingmixture of sulfolane and ASO as a function of the concentration ofhydrogen fluoride in the sulfolane-containing mixture.

The experimental method used to obtain the data presented in Table II issubstantially similar to that described in Example II. Variousconcentrations of hydrogen fluoride in the sulfolane-containing mixturewere established before contacting the mixture with an activated carbonmaterial. The data obtained are presented in Table II, whichunexpectedly demonstrates that the level of acid concentration in thesulfolane-containing mixture has a large impact upon the ASO adsorptioncapacity of activated carbon. These data are also plotted in FIG. 2.

                  TABLE II                                                        ______________________________________                                        The capacity of activated carbon to adsorb ASO from a                         sulfolane-containing mixture, having a ratio of sulfolane to                  ASO of 9 to 1, as a function of HF concentration.                             Concentration of                                                              HF in sulfolane-                                                                             Adsorption Capacity                                            containing Mixture                                                                           of Carbon                                                      Weight % HF    Weight % ASO on Carbon                                         ______________________________________                                        0.02           50                                                             0.10           19                                                             0.50            4                                                             1.00           Nil                                                            ______________________________________                                    

EXAMPLE IV

This Example IV demonstrates that various commercially availablealuminas can suitably be used to remove HF from a mixture of sulfolaneand ASO, either by adsorption or by neutralization. Also, this exampledemonstrates that alumina can also adsorb a portion of the ASO containedin the sulfolane-containing mixture as well as perform a neutralizationfunction.

The experimental method used to obtain the data presented in Table IIIis substantially similar to that described in Example II with theexceptions that the pH of effluent from the cylinder was monitored todetermine when the neutralization capacity of the alumina was reached.The sulfolane-containing mixture was provided with a 5 weight percentconcentration of HF. The data presented in Table III demonstrate thatvarious commercially available aluminas can suitably be used toneutralize a sulfolane-containing mixture with some adsorption of ASOprior to contacting the thus-neutralized mixture with an activatedcarbon material.

                  TABLE III                                                       ______________________________________                                        The capacity of various aluminas to neutralize and remove                     ASO from a sulfolane-containing mixture having a weight ratio                 of sulfolane to ASO of 9 to 1.                                                               Neutralization                                                                            ASO Adsorption                                                    Capacity    Capacity                                           Alumina Type   (meq* HF/g) (mg/g)                                             ______________________________________                                        LaRoche Alumina A-202                                                                        1.8          50                                                Alcoa Alumina HF-200                                                                         5.0         150                                                Engelhard Activated                                                                          1.3          35                                                Bauxite "Sure cat"                                                            LaRoche SAS Alumina                                                                          4.1         120                                                ______________________________________                                         *meq represents milequivalents                                           

EXAMPLE V

This Example V demonstrates that polyvinylpyridine reversibly adsorbsand desorbs HF from a mixture of sulfolane and ASO. Also, this exampledemonstrates that the polyvinylpyridine can also adsorb a portion of theASO contained in the sulfone-containing mixture as well as performing aneutralization function.

The experimental method used in this example is substantially similar tothat described in Examples II and IV, except that a metal reactor wasused instead of a glass cylinder in order to withstand pressures of upto 600 psig. In addition, the process and regeneration fluids werepumped across the absorbent bed rather than allowed to flow by force ofgravity.

A mixture of 90/10 (by volume) sulfolane/ASO+5% HF was pumped over a bedof 50 mL Reillex™ 425 polyvinylpyridine maintained at 100° F. andambient pressure. The mixture was pumped over the polymer at a rate of20 mL/hour. About 108 mL of effluent was collected before the pH of theeffluent dropped below 4.0. The feeding of the mixture was discontinuedfollowed by raising the bed temperature to about 300° F. and thepressure to 550 psig. Isobutane was passed over the polymer at a rate of30 mL/hour and under the aforementioned conditions. The isobutaneeffluent was initially quite dark and very acidic. Pumping of theisobutane was continued until the pH of the effluent was greater than6.0. At that point, the temperature and pressure were lowered to theirinitial conditions, and the sulfolane/ASO/HF mixture was again pumpedover the polymer. In the second contacting of the polyvinylpyridine bedwith the mixture, 100 mL of effluent was collected before its pH droppedto below 4.0, thus showing that regeneration with isobutane was fairlyefficient.

Calculations of the amounts of HF and ASO removed from thepolyvinylpyridine bed and obtained during the regeneration step showthat the polymer adsorbed about 5 mmole HF/gram polymer end about 80% ofthe ASO in the original sample mixture, measured cumulatively over theentire absorption part of the cycle.

EXAMPLE VI

This Example VI demonstrates that amine substituted styrenedivinylbenzene copolymers reversibly adsorb and desorb HF from a mixtureof sulfolane and ASO. Also, this example demonstrates that the aminesubstituted styrene divinylbenzene copolymers can also adsorb a portionof the ASO contained in the sulfone-containing mixture as well asperforming a neutralization function.

The experimental method used in this example is substantially similar tothat described in Examples II and IV, except that a metal reactor wasused instead of a glass cylinder in order to withstand pressures of upto 600 psig. In addition, the process and regeneration fluids werepumped across the absorbent bed rather than allowed to flow by force ofgravity.

A mixture of 90/10 (by volume) sulfolane/ASO+5% HF was pumped over a bedof 80 mL Rohm and Haas Amberlyst A-21, an amine substituted styrenedivinylbenzene copolymer, maintained at about 100° F. and ambientpressure. The mixture was pumped over the polymer at a rate of 30mL/hour. About 265 mL of effluent was collected before the pH of theeffluent dropped below 4.0. The feeding of the mixture was discontinuedand the resin was regenerated.

Calculations of the amounts of HF and ASO removed from the resin bed andobtained during the regeneration step show that the polymer adsorbedabout 5 mmole HF/gram polymer and about 70% of the ASO in the originalsample mixture, measured cumulatively over the entire absorption part ofthe cycle. FIG. 3 presents the results from this adsorption test. Thetime into the experimental run at which there was hydrogen fluoridebreakthrough is represented in FIG. 3 as the point of 100% of run. Thepercent ASO retained refers to the amount of ASO contained in the feedthat is removed by the resin and does not pass within the bed effluent.As is demonstrated by the adsorption curve, both ASO adsorption andhydrogen fluoride neutralization occur simultaneously.

While this invention has been described in terms of the presentlypreferred embodiment, reasonable variations and modifications arepossible by those skilled in the art. Such variations and modificationsare within the scope of the described invention and the appended claims.

That which is claimed is:
 1. A process comprising contacting asulfone-containing mixture, comprising a sulfone component andAcid-Soluble Oil (hereinafter "ASO"), with a particulate solid of areversible base selected from the group consisting of polyvinylpyridine,amine substituted styrene divinylbenzene copolymer and mixtures thereofunder conditions suitable for the removal of at least a portion of theASO component from said sulfone-containing mixture to produce a treatedsulfone-containing mixture.
 2. A process as recited in claim 1, whereinsaid reversible base is selected from a group consisting ofpoly-(2-vinylpyridine), poly-(4-vinylpyridine), and mixtures thereof. 3.A process as recited in claim 2, wherein the sulfone component of saidsulfone-containing mixture is sulfolane.
 4. A process as recited inclaim 3, wherein the ASO in said sulfone-containing mixture is presentin an amount no more than about 20 weight percent of the sulfonecomponent.
 5. A process as recited in claim 4, wherein the contactpressure is in the range of from 0.5 atmospheres of absolute pressure toabout 30 atmospheres of absolute pressure and the contact temperature isin the range of from about 0° F. to about 400° F.
 6. A process asrecited in claim 5, wherein said treated sulfone-containing mixturecomprises ASO at a concentration of less than about 2 weight percent. 7.A process comprising contacting a sulfone-containing mixture, comprisinga sulfone component, a hydrogen halide component, and Acid-Soluble Oil(hereinafter "ASO"), with a particulate solid of a reversible baseselected from the group consisting of polyvinylpyridine, aminesubstituted styrene divinylbenzene copolymer and mixtures thereof underconditions suitable for the removal of at least a portion of the ASOcomponent of said sulfone-containing mixture to produce a treatedsulfone-containing mixture.
 8. A process as recited in claim 7, whereinsaid reversible base is selected from a group consisting ofpoly-(2-vinylpyridine), poly-(4-vinylpyridine), and mixtures thereof. 9.A process as recited in claim 8, wherein the sulfone component of saidsulfone-containing mixture is sulfolane and the hydrogen halidecomponent of said sulfone-containing mixture is hydrogen fluoride.
 10. Aprocess as recited in claim 9, wherein the hydrogen halide component ispresent in said sulfone-containing mixture in an amount less than about10 weight percent of the total sum weight of hydrogen halide and sulfonecomponents and wherein the ASO in said sulfone-containing mixture ispresent in an amount no more than about 20 weight percent of the sumweight of hydrogen halide and sulfone components.
 11. A process asrecited in claim 10, wherein said treated sulfone-containing mixturecomprises hydrogen halide at a concentration of less than about 0.2weight percent.
 12. A process as recited in claim 11, wherein thecontact pressure is in the range of from 0.5 atmospheres of absolutepressure to about 30 atmospheres of absolute pressure and the contacttemperature is in the range of from about 0° F. to about 400° F.
 13. Aprocess for removing a contaminating amount of Acid-Soluble Oil(hereinafter "ASO") contained in a sulfone-containing mixture,comprising sulfolane, ASO, and HF, the process comprising: contactingsaid sulfone-containing mixture with a particulate solid of a reversiblebase selected from the group consisting of polyvinylpyridine, aminesubstituted styrene divinylbenzene copolymer and mixtures thereof underconditions suitable for the removal of at least a portion of saidcontaminating amount of ASO from said sulfone-containing mixture and forthe removal of at least a portion of said HF contained in saidsulfone-containing mixture to produce a treated sulfone-containingmixture containing a remaining portion of said contaminating amount ofASO and a reduced concentration of HF.
 14. A process as recited in claim13, wherein said reversible base is selected from a group consisting ofpoly-(2-vinylpyridine), poly-(4-vinylpyridine), and mixtures thereof.15. A process as recited in claim 14, further comprising: contactingsaid treated sulfone-containing mixture with carbon to thereby remove asubstantial portion of said remaining portion of said contaminatingamount of ASO to produce a substantially ASO free sulfone-containingmixture.
 16. A process as recited in claim 15, wherein the HF componentis present in said sulfone-containing mixture in an amount less thanabout 10 weight percent of the total sum weight of HF and sulfolanecomponents and wherein said contaminating amount of ASO in saidsulfone-containing mixture is no more than 20 weight percent of the sumweight of HF and sulfolane components.
 17. A process as recited in claim16, wherein said treated sulfone-containing mixture comprises saidreduced concentration of HF of less than about 0.2 weight percent.
 18. Aprocess as recited in claim 17, wherein said substantially ASO freesulfone-containing mixture has an ASO concentration of less than 2weight percent.
 19. A process comprising contacting a recovered catalystmixture, comprising sulfolane, Acid-Soluble Oil (hereinafter "ASO"), andHF, with a solid reversible base selected from the group consisting ofpolyvinylpyridine, amine substituted styrene divinylbenzene copolymerand mixtures thereof to thereby remove a significant portion of the HFcomponent of said recovered catalyst mixture to produce a neutralizedcatalyst mixture.
 20. A process as recited in claim 19, wherein saidreversible base is selected from a group consisting ofpoly-(2-vinylpyridine), poly-(4-vinylpyridine), and mixtures thereof.21. A process as recited in claim 20, further comprising: contactingsaid neutralized catalyst mixture with carbon to thereby remove asignificant portion of the ASO component of said neutralized catalystmixture to produce a regenerated catalyst mixture.
 22. A process asrecited in claim 21, further comprising:utilizing said regeneratedcatalyst mixture as at least a portion of a catalyst mixture, comprisingsulfolane and HF, and contacting a hydrocarbon mixture, comprisingolefins and isoparaffins, with said catalyst mixture within a reactionzone to thereby produce an alkylation reaction mixture, comprising analkylate product and ASO.
 23. A process as recited in claim 22, furthercomprising:separating said alkylate product from said catalyst mixturewithin a separation zone to produce a separated catalyst mixture,comprising a substantial amount of the ASO produced by said contactingstep of claim 22; and utilizing said separated catalyst mixture as atleast a portion of said catalyst mixture.
 24. A process as recited inclaim 23, further comprising: separating at least a portion of saidseparated catalyst mixture into a stream comprising said recoveredcatalyst mixture and a hydrogen fluoride stream, comprising HF.
 25. Aprocess as recited in claim 24, further comprising: utilizing saidhydrogen fluoride stream as at least a portion of said catalyst mixture.26. A process comprising: contacting a sulfone-containing mixture,comprising a sulfone component, a hydrogen halide component, andAcid-Soluble Oil (hereinafter "ASO") with a particulate solid of areversible base selected from the group consisting of polyvinylpyridine,amine substituted styrene divinylbenzene copolymer and mixtures thereofunder conditions suitable for the removal of at least a portion of thehydrogen halide component of said sulfone-containing mixture from saidsulfone-containing mixture to produce a neutralized sulfone-containingmixture.
 27. A process as recited in claim 26, further comprising:exposing said reversible base to a solvent under conditions such that atleast a portion of the ASO adsorbed by said reversible base during thecontacting step of claim 26 is removed by said solvent.
 28. A process asrecited in claim 27 wherein said solvent is an organic solvent selectedfrom the group consisting of alcohols, aliphatic hydrocarbons, alkylhalides, amines, aromatic hydrocarbons, esters, glycols, glycol ethers,aromatic halides, ketones and mixtures of two or more thereof.
 29. Aprocess as recited in claim 28, further comprising: exposing saidreversible base to a stripping fluid under stripping conditions so as toregenerate said reversible base.
 30. A process as recited in claim 29wherein the stripping conditions of the exposing step of claim 28include a stripping temperature in the range of from about 100°-600° F.and a stripping pressure in the range of from about 0.1 to 140atmospheres.
 31. A process as recited in claim 30 wherein said strippingfluid is selected from the group consisting of inert gases, steam andvaporous hydrocarbons.
 32. An alkylation process, comprising the stepsof:contacting a hydrocarbon mixture, comprising olefins andisoparaffins, with a catalyst mixture, comprising sulfolane and HF,within a reaction zone to thereby produce a reaction product and areaction by-product; separating said reaction product from said catalystmixture within a first separation zone to produce a separated reactionproduct and a separated catalyst mixture with said separated catalystmixture containing a substantial amount of said reaction by-product;utilizing said separated catalyst mixture as at least a portion of saidcatalyst mixture; passing at least a portion of said separated catalystmixture to a second separation zone to thereby separate said at least aportion of said separated catalyst mixture into a second separation zoneoverhead stream, comprising a major portion of the HF component of saidat least a portion of said separated catalyst mixture, and a secondseparation zone bottoms stream, comprising a major portion of thesulfolane component of said at least a portion of said separatedcatalyst mixture and a major portion of the reaction by-productcomponent of said at least a portion of said separated catalyst mixture;utilizing said second separation zone overhead stream as at least aportion of the HF component of said catalyst mixture; contacting saidsecond separation zone bottoms stream with a reversible base selectedfrom the group consisting of poly-(2-vinylpyridine),poly-(4-vinylpyridine), and mixtures thereof to thereby remove asubstantial portion of the HF contained in said second separation zonebottoms streams to produce a neutralized second separation zone bottomsstream; contacting said neutralized second separation zone bottomsstream with carbon to thereby remove a substantial portion of said majorportion of the reaction by-product to produce a sulfolane streamsubstantially free of said reaction by-product and HF; and utilizingsaid sulfolane stream as at least a portion of the sulfolane componentof said catalyst mixture.
 33. An alkylation process as recited in claim32, further comprising periodically exposing said reversible base to asolvent under conditions such that at least a portion of the reactionby-product adsorbed by said reversible base during the contacting stepof claim 32 is removed by said solvent.
 34. A process as recited inclaim 33 wherein said solvent is an organic solvent selected from thegroup consisting of alcohols, aliphatic hydrocarbons, alkyl halides,amines, aromatic hydrocarbons, esters, glycols, glycol ethers, aromatichalides and mixtures of two or more thereof.
 35. A process as recited inclaim 34, further comprising: exposing said reversible base to astripping fluid under stripping conditions so as to regenerate saidreversible base.
 36. A process as recited in claim 35 wherein thestripping conditions of the exposing step of claim 35 include astripping temperature in the range of from about 100°-600° F. and astripping pressure in the range of from about 0.1 to 140 atmospheres.37. A process as recited in claim 36 wherein said stripping fluid isselected from the group consisting of inert gases, steam and vaporoushydrocarbons.
 38. A process as recited in claim 1, further comprising:exposing said reversible base to a solvent under conditions such that atleast a portion of the ASO adsorbed by said reversible base during thecontacting step of claim 1 is removed by said solvent.
 39. A process asrecited in claim 38 wherein said solvent is an organic solvent selectedfrom the group consisting of alcohols, aliphatic hydrocarbons, alkylhalides, amines, aromatic hydrocarbons, esters, glycols, glycol ethers,aromatic halides and mixtures of two or more thereof.
 40. A process asrecited in claim 7, further comprising: exposing said reversible base toa solvent under conditions such that at least a portion of the ASOadsorbed by said reversible base during the contacting step of claim 7is removed by said solvent.
 41. A process as recited in claim 40 whereinsaid solvent is an organic solvent selected from the group consisting ofalcohols, aliphatic hydrocarbons, alkyl halides, amines, aromatichydrocarbons, esters, glycols, glycol ethers, aromatic halides andmixtures of two or more thereof.
 42. A process as recited in claim 41,further comprising: exposing said reversible base to a stripping fluidunder stripping conditions so as to regenerate said reversible base. 43.A process as recited in claim 42 wherein the stripping conditions of theexposing step of claim 42 include a stripping temperature in the rangeof from about 100°-600° F. and a stripping pressure in the range of fromabout 0.1 to 140 atmospheres.
 44. A process as recited in claim 43wherein said stripping fluid is selected from the group consisting ofinert gases, steam and vaporous hydrocarbons.
 45. A process as recitedin claim 13, further comprising: exposing said reversible base to asolvent under conditions such that at least a portion of the ASOadsorbed by said reversible base during the contacting step of claim 13is removed by said solvent.
 46. A process as recited in claim 45 whereinsaid solvent is an organic solvent selected from the group consisting ofalcohols, aliphatic hydrocarbons, alkyl halides, amines, aromatichydrocarbons, esters, glycols, glycol ethers, aromatic halides andmixtures of two or more thereof.
 47. A process as recited in claim 46,further comprising: exposing said reversible base to a stripping fluidunder stripping conditions so as to regenerate said reversible base. 48.A process as recited in claim 47 wherein the stripping conditions of theexposing step of claim 47 include a stripping temperature in the rangeof from about 100°-600° F. and a stripping pressure in the range of fromabout 0.1 to 140 atmospheres.
 49. A process as recited in claim 48wherein said stripping fluid is selected from the group consisting ofinert gases, steam and vaporous hydrocarbons.